Question
I have a large yukka that I keep outside, it getting good morning sunlight up till about 12pm. I have recently re-potted the plant and noticed that a quite a few ants fell from the roots, I gently shook the plant a more fell out, doing my best to remove most of the ants I then re-potted it. This is one of my concerns, plus its developed brown spots on the leaves...these developed prior to me re-potting. Can you please advice me on what the brown spots are and what to do about the ant invasion. I water sparingly...roughly every 4 weeks. Thanks in advance!

Answer
Nicola,

Since you are growing it outdoors you must live in a tropical area. It may be carpenter ants that are attacking it. They could be burrowing into the roots, yucca plants are hard to kill but carpenter ants might do it. The brown spots indicate root damage. I rarely use strong chemical because I am mostly dealing with plants in an indoor environment and I have allergies so I would not want to suggest to people to use strong chemicals that could be harmful in their homes. In this case your plant is outdoors and in mortal danger so I suggest that you visit your local garden center and describe your problem to them and see what they suggest. I imagine it will be a strong chemical that you can mix with water and drench the soil with it to kill the ants. My guess would be malathion. Be very careful applying whatever they suggest, use rubber gloves and get a breathing mask so you breath as few fumes as possible. I hope that when you repotted it you did not move it to too large a pot, not more that 2 inches larger diameter than the old pot. This plant is having a rough time already, too large a pot can cause overwatering and more problems. Treat that ant problem ASAP. Good luck.

Darlene